646795872 has 216 divisors, whose sum is σ = 2061750600. Its totient is φ = 191766528.

The previous prime is 646795861. The next prime is 646795879. The reversal of 646795872 is 278597646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646795879) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1581204 + ... + 1581612.

Almost surely, 2^646795872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646795872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1030875300).

646795872 is an abundant number, since it is smaller than the sum of its proper divisors (1414954728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646795872 is a wasteful number, since it uses less digits than its factorization.

646795872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 450 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 54.

The square root of 646795872 is about 25432.1818175319. The cubic root of 646795872 is about 864.8134057961.

The spelling of 646795872 in words is "six hundred forty-six million, seven hundred ninety-five thousand, eight hundred seventy-two".